Band-gap determination by photoreflectance of InGaAs and InAlAs lattice matched to InP

Abstract

Photoreflectance-derived band-gap parameters as a function of temperature for InGaAs and InAlAs lattice matched to InP are reported. The experiment was performed on a set of samples of various compositions (and strains) yielding greater reliability and ensuring self-consistency. For InGaAs, fits to the Varshni equation gave E0(T=0 K)=803 meV, α=4.0×10−4 eV K−1, and β=226 K. For InAlAs, E0(T=0 K)=1.541 eV, α=4.7×10−4 eV K−1, β=149 K, and Δ0=338 meV.